The ITU Radiocommunication Assembly considering a) that considerable progress in digital television standards has been achieved; b) that the Radiocommunication Study Group is responsible for setting the overall quality performance of broadcasting chains; c) that for television systems, ranging from low-definition systems 1 through SDTV to HDTV and including specific applications such as multiprogramming, it is essential to identify objective picture quality parameters as well as associated performance measurement and monitoring methods, for the studio environment and in broadcasting; d) that display technology, including fixed pixel displays, have digital pre-processing which may introduce unexpected artifacts, such as pixel rescaling, contrast ratio compensation, colorimetry correction, etc.; e) that it would be an advantage if measurement methods used for such tasks were unified for HDTV, SDTV and low-definition systems; f) that impairments to television pictures can be shown to correlate with measurable features of the signals; g) that overall picture quality is related to the combination of all impairments; h) that developments in the statistical characterization of television images and modelling of the human visual system may lead to the replacement of subjective assessment by objective measurement in certain applications; j) that in the case of digital TV it is necessary in particular to assess the performance of bit rate reduction methods both in terms of subjective and objective parameters; k) that the measurement of performance requires agreed standard test materials and methods based on moving and static images.